In a variety of networks, devices are connected to one another and to signal sources and power sources on the one hand, and to signal sinks or power loads on the other hand, by means of disconnectable plug-in connections. These disconnectable connections, which may be formed from plug parts and their mating parts, allow the rapid exchange of devices. Likewise, these connections are frequently used as test points during initial start-up and troubleshooting. However, the cabling is often susceptible to malfunctions, and the troubleshooting is often laborious.
It is known from DE 103 51 773 A1 and EP 1 818 859 B1 to provide the plug part with a transponder, in which an identifier is stored. The identifier is transmitted to the device to check whether the plug part is plugged into the correct mating part. This type of design of the plug part has only limited applications.
A software protection device for a textile machine is presented in Unexamined German Patent Application DE 10 2005 002 472 A1. The cited document describes how software may be protected from piracy by storing information in a so-called “dongle,” and how the machine functionality which is controlled via the software may be influenced in accordance with licensing.
The field of application is limited to textile machines, so that, among other things, it is not provided to link machine-specific data to other data stored in the dongle in order to thus enforce safety-relevant checks of certified, permissible hardware and software combinations, or to store data of peripheral devices, connected to a network, in the dongle and to interlink the data.
U.S. Pat. No. 7,014,500 B2 discloses a test method for identifying cables in star-shaped cable systems, the star point being a “patch panel.” As described, this system is used primarily in the field of computer cabling, in which a plurality of cables of the same type with an identical, and usually standardized, plug pin-wire conductor assignment is implicitly provided. This method is not suited for testing wiring by means of cable trees, which are customary in aircraft manufacturing or automobile manufacturing, for example, for the following reasons:    1) A cable tree, which by definition is made up of multiple wires (cable wires) which are locally branched, and in which not all wires of one cable from a first plug lead to exactly one second (remote) plug, but instead, the wires which are combined in a cable tree may be in an n:m relationship with multiple plugs.    2) The described test method must be uniform at all plugs, and two dedicated pins must be kept available for the test situation, which may not be the case for a large number of different sensors and actuators that are used.    3) In general, two wires of each plug must be continually provided for each plug for the test situation, which would represent a considerable material outlay.    4) It is a prerequisite that the wires reserved for the test situation must a priori be correctly wired (wire-to-pin assignment), and must have no cable break.    5) With the described test method, in the best case it is possible to check the correct functionality of the wires provided for the test situation (to test whether the test situation is functional), but not of the other wires of the same cable tree, which are necessary for the actual system functionality.    6) The described test method is not able to detect an incorrect plug pin-wire assignment, or short circuits between individual wire conductors, or breaks in individual wires.    7) Test setup and operation by one person is not provided.